As the field of conducting polymers has evolved, it is understood that commercially successful intrinsically conducting polymers (ICPs) require a cost effective synthesis in addition to fine balance of conductivity, processability, and stability. Over the last few years, researchers have utilized synthetic methods and techniques to attempt to control all three properties together. The synthesis of conjugated polymers, including the important polythiophene family of polymers, is usually divided into three polymerization techniques: electrochemical polymerization, oxidative chemical polymerization using metal-based oxidant, and transition metal promoted cross-coupling of organic dihalide groups. For example, the application of these polymerization techniques in the synthesis of polythiophene is described in detail in McCullough, Adv. Mater. 10(2):93-116 (1998), which is incorporated herein by reference in its entirety. See also, for example, U.S. Pat. No. 6,166,172 (GRIM polymerization method); U.S. Pat. No. 6,602,974 (block copolymers); and U.S. Pat. No. 7,452,958 (living polymerization). In some embodiments, iodonium salts have been employed for oxidative polymerization of thiophene monomers. (see, for example, Yagci, Y et al, Macromol. Chem. Phys. 2005, 206, 1178-1182)
Although these polymerization methods can be useful in the synthesis of conjugated polymers, they still possess a number of limitations, including (a) difficulties in generating large amounts of processable, pure materials; (b) problems in polymerizing many monomers with sensitive/reactive functional groups; and (c) multiple intermediate (synthesis and/or purification) steps in the synthetic route which increases the cost of final products and complicates the development, manufacturing and commercialization processes.
A need exists for improved methods for producing electrically conductive polymers that are fast, reliable, and cost effective.